Memory devices, such as flash memory, are widely used in computers and many electronic items. Some memory devices may include memory cells stacked vertically to form three-dimensional (3D) blocks of memory components. Blocks of memory may be tagged as defective during manufacturing testing or during user operations, and these blocks may thereafter be unusable. As 3D memory block size is increased, tagging blocks as defective may result in larger amounts of memory becoming unusable by users.